PROJECT SUMMARY/ABSTRACT Loss of cognitive abilities leading to Alzheimer's disease is progressive and destructive, leaving older adults disabled and unable to recall their past. The number of older adults with Alzheimer's disease is expected to triple by the year 2050, yet little research examines amyloid beta (A?) deposition, executive function, and progression of disability. Even less examines non-pharmacological interventions designed to slow progression to disability for these older adults. We propose to test the influence of a novel and promising non- pharmacological intervention on progression of disability in a sample of 150 older adults with Mild Cognitive Impairment (MCI) who have previously completed Positron Emission Tomography (PET) Imaging with Pittsburgh Compound B (PiB). Our intervention is Strategy Training. Strategy training optimizes engagement in meaningful daily activities through generating self-selected goals, monitoring daily activities, scheduling activities, and problem-solving solutions to barriers experienced when engaging in activities. Occupational therapists deliver Strategy Training in older adults' homes to enhance real-world application. We completed a preliminary randomized controlled trial of Strategy Training (N=30), and we found a moderate effect size (Cohen's d = 0.54) for between-group differences on disability at 6 months. In this Phase II trial, we will test the effect of Strategy Training compared to Enhanced Usual Care on change in disability among older adults with MCI and assess the extent to which brain imaging and neurocognitive function modify the relationship between Strategy Training and Enhanced Usual Care on change in disability. Interventions, such as Strategy Training, focused on slowing emergence of disability despite underlying pathology may keep older adults as engaged in meaningful daily activities for as long as possible. This project tests a novel and promising non- pharmacological intervention and will inform our understanding of important effect modifiers -A? deposition and executive function- on change in performance of cognitively challenging daily activities. Enhancing our understanding of A? deposition, executive function, disability, and a promising non-pharmacological intervention could support aging for millions of older adults who, in our near future, will experience disability related to MCI.